Don't get me wrong, I'm not with the whole Moon's Eye plan. He's a prick for that, of course. But just recently I've come to this very tragic realization: Obito is a 30-year-old virgin. That's one mean case of blue balls....or ball.
But it's his fault really. Instead of being all butthurt over Rin's death, he should have seized the opportunity while in Kirigakure and started caking with a then-17-year-old Mei. You know.